1) Technical Field
The subject invention relates to removable fuel caps for automotive fuel tanks.
2) Description of the Prior Art
Most vehicle fuel tanks include a filler neck extending from the tank to allow a user to refill the tank with fuel. Some type of cap or cover is placed over the filler neck in order to seal the fuel tank from the atmosphere. The most common type of cover is a removable fuel cap or gas cap.
Conventional removable fuel caps typically include a housing for threading onto the filler neck and a handle rotatably mounted to the housing. The housing usually includes at least one seal for sealing engagement with the filler neck. Many of these removable fuel caps have ratcheting mechanisms disposed between the handle and the housing wherein the handle may rotate about the housing. The ratcheting mechanisms ensure that only a predetermined amount of torque is applied to the housing. In other words, the housing cannot be overtightended to the filler neck. Overtightening of the housing could increase the compression of the gasket and prematurely age the gasket. Examples of such mechanisms are shown in U.S. Pat. Nos. 3,820,680; 4,299,102; and 4,676,390.
Other conventional fuel caps may also include a "lost motion" feature between the handle and the housing. The lost motion connection provides a level of safety in the event of an impact. Specifically, the handle can rotate independently of the housing such that the seal of the housing remains in sealing engagement with the filler neck. An example of such a design is illustrated in U.S. Pat. No. 5,480,055. The prior art fuel cap designs which incorporate lost motion features suffer from a number of deficiencies. One deficiency is the relative complexity of the design which equates to costly manufacturing and assembly. Another deficiency relates to the limitations of the lost motions connects, primarily the limited rotational distance in which the handle may rotate relative to the housing.